My best online accounting experience so far has been with Xero. Xero has pretty good bank and payroll feed integration, good customizable tracking classes, and it's geared towards the small business user. It ends up being a little pricier than buying a prior year desktop version of QuickBooks but it seems to be the best online package and they're actually pushing and working to make accounting easier vs. QuickBooks online which has just been a poor version of their desktop software.

There are lots of tradeoffs but it mostly comes down to 1. bookkeeping skill/comfort level and 2. budget. A good third thing to consider is whether you'll need to get your data to an accountant and if so, can you do this in a format that will be usable by them.

I haven't seen the QB online refresh yet so that might have improved.

I used Wave as recently as a year ago (had a client using it) and it was frustrating to pull any sort of meaningful reporting from and it lacked some functionality.